Portable devices that store and play digital audio files (e.g, MP3, WAV, ACC, and other such audio formats) have become increasingly popular in recent years. A digital audio device may comprise a relatively slim casing having a display and a control (e.g., a touch-scroll wheel and a group of buttons) disposed thereon. The casing contains a battery (e.g., a lithium ion cell), a circuit board, and a hard drive, which may be sheathed in a soft rubber to insulate the hard drive from the circuit board and to protect it from shock damage. The hard drive's capacity may range from, for example, 512 MB to 60 GB in size and store anywhere from 120 to 15,000 audio files, respectively.
To use a portable digital audio device, a user first builds a library of audio files on his or her home computer by downloading purchased songs from an internet site (e.g., the iTunes website) or by uploading converted songs from owned CDs or other media. A user may transfer selected audio files from his or her computer to the portable digital audio device via a docking station and associated software (e.g., iTunes media library software). The docking station may be coupled to the home computer via, for example, a universal serial bus or firewall port and to the digital audio device through a specialized connector port (e.g., a 30-pin connector port).
Consumers have shown a desire to utilize their portable digital audio devices in conjunction with their vehicular audio systems to, for example, play audio files with the vehicle's audio system. FM transmitters have been developed that connect to the digital audio device and broadcast music played thereby over an output frequency (e.g., 87.9 MHz) that may be received by the vehicle's FM radio. Certain audio systems provide auxiliary inputs that may be connected to the headphone output of a digital audio device via an audio interconnect cable. More recently, several automotive manufacturers have begun offering digital audio device interfaces permitting bi-directional communication between the vehicle's audio system and a digital audio device. After connecting a digital audio device to the interface (e.g., via a connector cable stowed in the vehicle's glove box), a driver may then control the device through the vehicle's audio system (e.g., through audio system controls mounted on the steering wheel) to select digital audio files to be played by the audio system system.
While providing users with the ability to play digital audio files with their vehicle's audio system, vehicular digital audio device integration systems of the type described above may be somewhat cumbersome to use. Systems utilizing FM modulators or audio interconnect cables require a user to utilize the controls provided on the digital audio device to select and play songs, which may be inconvenient. Furthermore, when using any of above-described integration systems, a user must repeatedly transport a digital audio device (and possibly other hardware) to and from his or her vehicle and perform the iterations necessary to properly connect the device to the integration system's interface.
In view of the above, it should be appreciated that it would be desirable to provide a system for playing digital audio files on a vehicle's audio system that utilizes a reduced number of required components. Furthermore, it should be appreciated that it would be advantageous if such a system facilitates access to the digital audio files. Other desirable features and characteristics of the present invention will become apparent from the subsequent detailed description and the appended claims, taken in conjunction with the accompanying drawings and the foregoing technical field and background.